On Tue, 03 Aug 2010 06:19:49 -0700, Jonathan Mueller wrote: |To illustrate how even as adults we can struggle with some problems |like conservation, I tell my students the story of following a truck. |You are on the road and you find yourself behind a slow semi. You |notice that as the semi is approaching a bridge the driver pulls a |baseball bat out of his cab and bangs on the side of his truck. You |think this is odd. But you notice that he does this every time he |comes to a bridge. Now you are so curious you just have to find |out why. So, you follow the truck driver until he stops. You go |up to him and ask him why he was hitting his truck with a baseball bat. |he says, "Well, you see, I am carrying a load of live birds in the back |that weigh 8 tons. And my truck weighs 8 tons. The signs for the |bridges say you can only weigh 8 tons going over them. So, I bang |on the side of my truck, the birds fly up in the air, and then my truck |only weighs 8 tons." I ask my class if the truck driver is right.
I feel like I'm entering a Monty Python sketch on European versus African sparrows but the examples used in the Mythbusters show had closed spaces, so, when a helicopter flew or birds beat their wings, the forces they generated were confined to the closed system of the container. What happens to the weight of the container if it is an open system, that is, there are slats on the side of the container with the birds so that when they are in flight in the container, the force generated by their wings can be displaced out of the container? That being said, I would make sure that I am about 200 feet away from a truck like that described above going over a bridge with an 8 ton carrying capacity. -Mike Palij New York University [email protected] --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=3951 or send a blank email to leave-3951-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
